Electrospray ion source

Abstract

The utility model relates to an electrospray ion source belongs to mass spectrum monitoring technical field to solve the existing electrospray ion source, there is launcher manufacturing cost is high, one -time difference, launcher is easy to block, and electrospray efficiency is low, and sample is easy to remain, and mass spectrum monitoring precision is low and the problem that monitoring operation is complicated. The present application includes mass spectrometer, mounting bracket, electric contact device and launcher, and mass spectrometer is fixedly installed in mounting bracket, and it is equipped with high -voltage wire and mass spectrum sample inlet, electric contact device is fixedly installed in the mounting bracket near mass spectrum sample inlet side, and it is equipped with launcher installation cavity and the first needle that extends to mass spectrum sample inlet, and the first needle is electrically connected with high -voltage wire, the launcher is installed in launcher installation cavity, and the launcher inside is equipped with sample cavity and the second needle that is installed in the first needle inside, the second needle is blocked in the first needle, and part second needle extends to the first needle outside. The present application is simple in structure, and the cost of making is low, and convenient operation.

Description

Technical Field

[0001] This utility model relates to an electrospray ionization source, belonging to the field of mass spectrometry monitoring technology. Background Technology

[0002] A mass spectrometer is an instrument used to analyze the composition of samples. It works by ionizing sample molecules and then separating and detecting them based on their mass-to-charge ratio. The ion source is a crucial component, and different ion sources are suitable for different types of samples. Electrospray ionization (ESI), a revolutionary technology in mass spectrometry, was invented by John Fenn's team. They applied high pressure to a liquid passing through a capillary tube to charge the sample, forming charged droplets. As the solvent evaporated, the charge concentrated on the molecules, ultimately generating ions. This process is relatively gentle, allowing the sample to form multi-charged ions, significantly reducing the mass-to-charge ratio (m / z). This enables quadrupole mass spectrometers and other mass spectrometers to detect very large molecules (such as proteins), and this ionization technique remains in use today. In addition to conventional electrospray ionization sources, nano-electrospray ionization (Nano-ESI) is also commonly used. Nano-ESI was proposed by Wilm and Mann and was developed based on conventional ESI for low flow rate and high sensitivity. It is made of glass capillary with the orifice diameter reduced to 1-2 μm. The liquid sample is added into the glass capillary and then inserted into a platinum wire with high voltage to generate charged droplets.

[0003] Conventional ESI requires the use of a pump or flow injection device to directly introduce the liquid sample into the ion source at a high flow rate, typically ranging from 1 to 1000 μl / min. For nanoESI, there are three basic structural units: the emitter, the electrical contact, and the sample injection point. Charged droplets are ejected directly from the emitter. Generally, the smaller the emitter size, the smaller the diameter of the charged droplets produced in Taylor cone mode, which is beneficial for converting more analytes into gaseous ions and improving ionization efficiency. The single emitter is the original form of nanoESI and the most widely used emitter type. The basic form of a single emitter is a silica capillary, which is heated, melted, drawn, and then separated to produce a cone-shaped emitter with a very fine internal dimension at one end. Commercial companies often use laser-heated capillary pullers to manufacture ultrafine emitter tips. Both methods are very expensive to manufacture single emitters, requiring a separate, costly capillary puller. Furthermore, the emitter orifice diameter produced by these methods varies greatly, resulting in poor consistency; the manufacturing process is also time-consuming and inefficient. Secondly, the emitter is prone to clogging, which reduces the efficiency of electrospraying and may even interrupt the experiment. The clogging is caused by the fact that the smaller aperture is more easily blocked by impurities in the air and solution. On the other hand, the inner diameter of commercial nano-emitters changes suddenly many times, causing fluid disturbance and impurity accumulation in these places.

[0004] Since nanoESI emitters are typically made of non-conductive fused silica, inserting a conductive wire into the emitter is a common electrical contact method. When changing samples, the previous solution can easily remain on the conductive wire, contaminating the new sample. Furthermore, traditional nanoESI interfaces connect to the end of the separation column or injection needle, requiring the sample to be placed in a syringe or sample vial before being pumped through the injection pump or chromatography pump to deliver the sample solution to the nanoESI interface. This results in low feed efficiency, necessitates repeated equipment adjustments to ensure the feed rate of the injection pump or chromatography pump is compatible with the mass spectrometer's detection, and is cumbersome. Therefore, an electrospray ionization source is needed to address the problems of existing electrospray ionization sources, including high emitter manufacturing costs, poor perishability, easy clogging of the emitter, low electrospray efficiency, easy sample residue, low mass spectrometry monitoring accuracy, and cumbersome monitoring operations. Utility Model Content

[0005] The purpose of this invention is to provide an electrospray ion source to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: an electrospray ionization source, comprising a mass spectrometer, a mounting frame, an electrical contact device, and an emitter. The mass spectrometer is fixedly mounted on the mounting frame and has a high-voltage lead wire and a mass spectrometer inlet. The electrical contact device is fixedly mounted on the mounting frame near the mass spectrometer inlet and has an emitter mounting cavity and a first needle extending to the mass spectrometer inlet. The first needle is electrically connected to the high-voltage lead wire. The emitter is mounted in the emitter mounting cavity, and the emitter has a sample cavity and a second needle mounted inside the first needle. The second needle abuts against the first needle, and a portion of the second needle extends to the outside of the first needle.

[0007] Specifically, the mounting frame includes a base and a bracket. The bracket is vertically mounted on the base, the mass spectrometer is fixedly mounted on the base, and the electrical contact device is fixedly mounted on the bracket.

[0008] Specifically, the electrical contact device includes a connecting frame, a connecting seat, and a connecting member; the connecting seat has openings on both sides and a hollow internal structure to form a transmitter mounting cavity; the connecting member has openings on both sides and a hollow internal structure to form a second needle mounting cavity; the connecting frame is fixedly mounted to the mounting frame by mounting bolts, the connecting seat is detachably mounted to the connecting frame, and the connecting member is mounted on the opening facing the mass spectrometer injection port; a first needle is mounted on the side of the connecting member away from the connecting seat.

[0009] Specifically, the connecting frame is provided with a mounting groove that matches the shape of the connecting seat, and a first threaded hole is opened on the outer side of the connecting frame corresponding to the mounting groove and facing the mounting groove. The connecting seat is slidably installed in the mounting groove, and a first bolt is threadedly installed in the first threaded hole. The connecting seat is fixedly installed in the connecting frame by the first bolt abutting against the seat body. A second threaded hole is opened on the outer side of the seat body facing the transmitter mounting cavity. The connecting piece is slidably installed in the transmitter mounting cavity, and a second bolt is threadedly installed in the second threaded hole. The connecting piece is fixedly installed in the connecting seat by the second bolt abutting against the connecting piece. The first needle is threadedly installed in the seat body of the connecting piece away from the connecting seat.

[0010] Specifically, the connector has a socket for installing high-voltage wires.

[0011] Specifically, the connector and connector base are made of insulating material, the connector is made of conductive material, and the first needle is made of conductive material.

[0012] Specifically, the transmitter includes a syringe and a second needle; the syringe is installed in the transmitter mounting cavity, and the shape of the transmitter mounting cavity is adapted to the shape of the syringe; the second needle is detachably installed at the end of the syringe.

[0013] Specifically, the syringe is a disposable screw-type syringe; the second needle is made of conductive material and is a disposable screw-type needle that is threadedly connected to the syringe.

[0014] Specifically, the inner diameter of the first needle is matched with the outer diameter of the second needle.

[0015] Specifically, the first needle forms a 60° angle with the mass spectrometer injection port.

[0016] Compared with the prior art, the beneficial effects of this utility model are: 1. The electrospray ionization source of this application comprises an electrical contact device and an emitter mounted on a mounting frame. The electrical contact device is equipped with a first needle, and the emitter is equipped with a second needle, which is installed inside the first needle. By mounting a mass spectrometer on the mounting frame and electrically connecting the high-voltage lead of the mass spectrometer to the first needle, high voltage is provided through the high-voltage lead, and current is transmitted to the first and second needles, causing the sample in the emitter to be sprayed. Mass spectrometry monitoring and analysis are then performed by the mass spectrometer's mass spectrometry inlet. The electrospray ionization source of this application improves upon the high manufacturing cost of traditional emitters. The electrical contact device does not directly contact the sample, solving the sample contamination problem of traditional nanoESI, and the monitoring results are highly accurate.

[0017] 2. Based on the foregoing, the mounting frame of this application includes a fixed base and a fixed bracket. The fixed bracket is vertically mounted on the fixed base, the mass spectrometer is fixedly mounted on the fixed base, and the electrical contact device is fixedly mounted on the fixed bracket. The electrical contact device includes a connecting frame, a connecting base, and a connecting member. The connecting frame is directly mounted on the fixed bracket. The connecting base of this application is detachably mounted on the connecting frame via a first bolt, and the connecting member is detachably mounted on the connecting base via a second bolt. The first needle is threadedly connected to the base of the connecting member away from the connecting base. The transmitter is directly mounted on the connecting base, resulting in a simple overall structure and convenient installation.

[0018] 3. Based on the foregoing, the first needle, connector, and second needle of this application are all made of conductive material. The connector has a socket for installing a high-voltage wire, so that by directly installing the high-voltage wire into the socket, the connector is electrically connected to the high-voltage wire, thereby achieving an electrical connection between the first and second needles and the high-voltage wire. The sample feeding operation of this application is simple and does not require repeated adjustments. The high-voltage wire is boosted by the mass spectrometer, and the high voltage is transmitted to the second needle through the connector and the first needle, thus achieving continuous spraying of the sample in the emitter and high monitoring efficiency.

[0019] 4. Based on the foregoing, the syringe of this application is a disposable screw-in syringe, and the second needle is a disposable screw-in needle threadedly connected to the syringe. The second needle of this application uses a low-cost screw-in needle available on the market, with inner diameters of 0.11mm and 0.06mm selectable according to usage requirements. This needle has a stable orifice diameter, which does not change significantly during large-scale production. Furthermore, using a needle with the smallest orifice diameter of 0.06mm reduces the risk of clogging, and liquid will not naturally flow out of the needle hole, further reducing monitoring costs. In addition, the inner diameter of the first needle in this application is matched with the outer diameter of the second needle to enable quick installation of the transmitter, ensuring a stable connection between the first and second needles and improving monitoring efficiency. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the electrospray ion source in this embodiment; Figure 2 This is an exploded view of the electrical contact device of the electrospray ion source in this embodiment; Figure 3 This is a schematic diagram of the installation structure of the contact device and emitter of the electrospray ion source in this embodiment. Figure 4 This is a schematic diagram of the sample loading and unloading process of the electrospray ion source emitter in this embodiment.

[0021] In the diagram: 1. Mass spectrometer; 2. Mount; 3. Mounting bracket; 4. High-voltage wire; 5. Mass spectrometer inlet; 6. First needle; 7. Second needle; 8. Connecting frame; 9. Connecting seat; 10. Connector; 11. First bolt; 12. Second bolt; 13. Disposable screw-type syringe. Detailed Implementation

[0022] To make the objectives and advantages of this utility model clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the following text is merely used to describe one or more specific embodiments of this utility model and does not strictly limit the scope of protection specifically claimed by this utility model.

[0023] Please see Figures 1-4 This embodiment discloses an electrospray ionization source, including a mass spectrometer 1, a mounting frame, an electrical contact device, and an emitter. The mounting frame of this embodiment includes a fixed base 2 and a fixed bracket 3. The fixed bracket is vertically mounted on the fixed base. The mass spectrometer 1 is fixedly mounted on the fixed base and has a high-voltage lead wire 4 and a mass spectrometer inlet 5. The electrical contact device is fixedly mounted on the fixed base near the mass spectrometer inlet and has an emitter mounting cavity and a first needle 6 extending to the mass spectrometer inlet. The first needle forms a 60° angle with the mass spectrometer inlet and is electrically connected to the high-voltage lead wire. The emitter is mounted in the emitter mounting cavity. The emitter has a sample cavity inside and a second needle 7 installed inside the first needle. The second needle abuts against the first needle, and part of the second needle extends to the outside of the first needle.

[0024] The electrical contact device of this embodiment includes a connecting frame 8, a connecting seat 9, and a connector 10. The connecting seat is a circular cavity structure with openings on both sides and a hollow interior, the hollow interior forming an emitter mounting cavity. The connector is also a circular cavity structure with openings on both sides and a hollow interior, its hollow interior forming a second needle mounting cavity. The connecting frame is fixedly installed on the fixed bracket by mounting bolts, while the connecting seat is detachably installed on the connecting frame by mounting bolts, and the connector is installed on the opening facing the mass spectrometer injection port. A first needle is installed on the side of the connector away from the connecting seat.

[0025] Preferably, in this embodiment, the connecting frame 8 is provided with a mounting groove that matches the shape of the connecting seat, and a first threaded hole is opened on the outer side of the connecting frame corresponding to the mounting groove in the direction of the mounting groove. The connecting seat 9 is slidably installed in the mounting groove, and the first bolt 11 is threadedly installed in the first threaded hole. The connecting seat is fixedly installed on the connecting frame by the first bolt against the seat body. The outer side of the connecting seat is provided with a second threaded hole of M2 facing the transmitter mounting cavity. The connecting member 10 is slidably installed in the transmitter mounting cavity, and the second bolt 12 is threadedly installed in the second threaded hole. The connecting member is fixedly installed on the connecting seat by the second bolt against the connecting member. In addition, in this embodiment, the end of the connecting member away from the connecting seat is provided with a third threaded hole of M3.5 inward. The outer side of the first needle 6 is provided with an external thread, and it is threadedly installed on the seat body of the connecting member away from the connecting seat.

[0026] Furthermore, the connector in this embodiment has a φ3.2mm diameter insertion hole for installing and inserting a high-voltage plug. The connector frame and connector base in this embodiment are made of insulating material, with the connector base made of PTFE. Both the connector and the first needle are made of stainless steel, with the first needle being a precision stainless steel needle with an internal diameter of 0.25mm.

[0027] The transmitter in this embodiment includes a disposable screw-in syringe 13 and a second needle 7. The disposable screw-in syringe is installed in the transmitter mounting cavity, and the shape of the transmitter mounting cavity is adapted to the shape of the disposable screw-in syringe. The second needle is a disposable screw-in needle, which is detachably installed at the end of the disposable screw-in syringe via a threaded connection. The second needle in this embodiment consists of a plastic screw and a stainless steel needle. The total length of the needle is 30mm, the exposed length of the stainless steel needle is 13mm, the outer diameter of the needle is 0.23mm, and the inner hole diameter is available in two specifications: 0.11mm and 0.06mm. The needle with the smallest hole diameter of 0.06mm is preferred, as it is less prone to clogging, and the sample liquid will not flow out of the needle hole under natural conditions.

[0028] Working principle: Before using the electrospray ionization source in this embodiment, a sample needs to be loaded. The operator first replaces the original needle on the disposable screw-type syringe with a screw-type stainless steel needle, i.e., the second needle. After replacing the needle, the operator slowly raises the syringe plunger to draw up the liquid sample. Because the needle orifice is very small, the liquid sample will slowly enter the syringe barrel. After drawing up an appropriate volume of sample, the operator needs to slowly pull out the plunger to complete the sample collection.

[0029] Next, the operator inserts the sampled syringe directly into the transmitter cavity of the connector, with the second needle making contact with the first needle, and part of the second needle protruding from the needle hole of the first needle. The insertion depth of the syringe is adjusted to regulate the distance between the second needle and the mass spectrometer inlet. After adjusting the distance, the plug of the high-voltage wire is inserted into the socket of the connector, thus completing the component installation and debugging before monitoring.

[0030] During monitoring, the mass spectrometer is activated, and the current in the high-voltage lead wire is supplied by the mass spectrometer. The high voltage is conducted to the screw-type stainless steel needle tip, and the sample is continuously ejected under high voltage, forming a continuous and stable electrospray. The second needle forms a 60° angle with the mass spectrometer inlet to further assist sample outflow. When it is necessary to change the sample, simply pull out the disposable screw-type syringe and insert the next disposable screw-type syringe with the sample into the electrocontamination device. The whole process is quick and convenient. Since the electrocontamination device does not directly contact the sample, there is no risk of sample cross-contamination.

[0031] The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. For those skilled in the art, after learning the contents of the present invention, several equivalent changes and substitutions can be made without departing from the principle of the present invention. These equivalent changes and substitutions should also be considered to fall within the protection scope of the present invention.

Claims

1. An electrospray ionization source, comprising a mass spectrometer, a mounting bracket, an electrical contact device, and an emitter, characterized in that: The mass spectrometer is fixedly mounted on a mounting frame, which has a high-voltage lead wire and a mass spectrometer inlet. The electrical contact device is fixedly mounted on the mounting frame near the mass spectrometer inlet, and it has an emitter mounting cavity and a first needle extending to the mass spectrometer inlet. The first needle is electrically connected to the high-voltage lead wire. The emitter is mounted in the emitter mounting cavity, and the emitter has a sample cavity and a second needle mounted inside the first needle. The second needle abuts against the first needle, and part of the second needle extends to the outside of the first needle.

2. The electrospray ionization source according to claim 1, characterized in that: The mounting frame includes a fixed base and a fixed bracket. The fixed bracket is vertically mounted on the fixed base, the mass spectrometer is fixedly mounted on the fixed base, and the electrical contact device is fixedly mounted on the fixed bracket.

3. The electrospray ionization source according to claim 1, characterized in that: The electrical contact device includes a connecting frame, a connecting seat, and a connecting member; the connecting seat has openings on both sides and a hollow internal structure to form a transmitter mounting cavity; the connecting member has openings on both sides and a hollow internal structure to form a second needle mounting cavity; the connecting frame is fixedly mounted to the mounting frame by mounting bolts, the connecting seat is detachably mounted to the connecting frame, and the connecting member is mounted on its opening facing the mass spectrometer injection port; a first needle is mounted on the side of the connecting member away from the connecting seat.

4. An electrospray ionization source according to claim 3, characterized in that: The connecting frame is provided with a mounting groove that matches the shape of the connecting seat, and a first threaded hole is opened on the outer side of the connecting frame corresponding to the mounting groove and facing the mounting groove. The connecting seat is slidably installed in the mounting groove, and a first bolt is threadedly installed in the first threaded hole. The connecting seat is fixedly installed in the connecting frame by the first bolt abutting against the seat body. A second threaded hole is opened on the outer side of the seat body facing the transmitter mounting cavity. The connecting piece is slidably installed in the transmitter mounting cavity, and a second bolt is threadedly installed in the second threaded hole. The connecting piece is fixedly installed in the connecting seat by the second bolt abutting against the connecting piece. The first needle is threadedly installed in the seat body of the connecting piece away from the connecting seat.

5. An electrospray ionization source according to claim 3, characterized in that: The connector has a socket for installing high-voltage wires.

6. An electrospray ionization source according to claim 3, characterized in that: The connecting frame and connecting base are made of insulating material, the connecting parts are made of conductive material, and the first needle is made of conductive material.

7. An electrospray ionization source according to claim 1, characterized in that: The transmitter includes a syringe and a second needle; the syringe is installed in a transmitter mounting cavity, and the shape of the transmitter mounting cavity is adapted to the shape of the syringe; the second needle is detachably installed at the end of the syringe.

8. An electrospray ionization source according to claim 7, characterized in that: The syringe is a disposable screw-in syringe; the second needle is made of conductive material and is a disposable screw-in needle that is threadedly connected to the syringe.

9. An electrospray ionization source according to claim 1, characterized in that: The inner diameter of the first needle is matched with the outer diameter of the second needle.

10. An electrospray ionization source according to claim 1, characterized in that: The first needle forms a 60° angle with the mass spectrometer injection port.

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